Crowd Power: The Latest In Renewable Energy

Vibrations from passing trucks, the rumbling of speeding trains and even the footfall of busy city commuters could be captured and converted into energy to light walkways and buildings, engineers say. A London-based architectural firm is working on a project that aims to harness the pulse of a city and use it as a renewable energy source. Facility Architects director Clair Price says tens of thousands of people can pass through urban hubs like train stations during rush hour. "You don't need to be a maths genius to realise that if you can harness that energy... you can actually generate a very useful power source that is currently being wasted," she says. Price's team has financial and technical support from several organisations for the proposal. "My first reaction when I saw it was wow, this is fantastic," says Tony Bates, business development manager at Scott Wilson, an engineering consultancy firm based in the UK. "As an engineer of course, you can really see that this can really work."

Bates and Price are now in the process of developing a joint partnership to make the idea a reality. The architectural team is working with university research groups to finish two vibration-harvesting prototypes by December. The first is a staircase that will contain hydraulic or piezoelectric technology in the risers. The technology will pick up kinetic energy from commuter footfalls and convert it into an electrical current.

Climbing stairs requires more force, which means there's more energy to be tapped. Engineering experts from the University of Hull hope to develop a system that will convert at least 50% of the six to eight watts each person typically generates while walking. The current will be stored in a battery, which can be used to provide energy for lighting or electronic devices. The second prototype is a wireless lighting system that will use tiny generators with components designed to resonate at the same frequency as surrounding vibrations. The resonance will either move a magnet relative to a coil or put stress on a crystalline structure inside a generator to produce a current. Light-emitting diodes connected to such vibration harvesters could illuminate the underside of arches.